This study seeks to improve clinical care for peripheral and central vestibular disorders by translating recent advances in vestibular physiology to clinical practice. Vertigo and dizziness lead to 4 million US emergency department (ED) visits annually at a cost of $4 billion. Most of the ~1 million patients with peripheral vestibular causes for their symptoms are over-tested, misdiagnosed, and undertreated. Hundreds of millions of dollars are spent on neuroimaging (~$500M CT, ~$100M MRI) trying to detect the ~5% of patients who have life-threatening posterior fossa strokes causing their vertigo - yet one-third of these vestibular strokes are missed. Accurate and efficient diagnosis will save lives and reduce costs through prompt and appropriate treatments. Our team has studied dizziness in the ED for more than a decade. We have developed a new approach to differentiate benign peripheral causes from dangerous central ones by careful assessment of three vestibular eye movements (HINTS: Head Impulse, Nystagmus, Test of Skew) and hearing. Our approach enables rapid physiologic diagnosis at the bedside with greater accuracy than MRI brain scans in the first two days after the onset of acute, continuous vertigo or dizziness. This approach has been validated in over 200 patients. Similar, well-established bedside techniques (e.g., Dix-Hallpike test) work to diagnose intermittent, position-provoked vertigo. Unfortunately, these eye movement tests are unfamiliar to most ED physicians, and even to many specialists. A new video-oculography (VOG) device that measures these eye movements quantitatively at the bedside has the potential to transform diagnosis for ED patients with dizziness and vertigo. The device is easy to use, measures eye movements accurately, and requires no more patient cooperation than a bedside exam of the cranial nerves. We have shown initial proof that the device correctly diagnoses acute vestibular strokes. We propose the AVERT trial (Acute Video-oculography for Vertigo in Emergency Rooms for Rapid Triage), a multicenter, randomized, Phase II clinical trial of VOG-guided vs. standard care to improve diagnosis and initial management for patients with a chief symptom of vertigo or dizziness suspected to be of vestibular cause. We will recruit 226 adults from 3 EDs. We will perform bedside VOG and portable audiometry on all subjects, who will then be randomized to VOG-guided vs. standard care. In the VOG arm, patients will be diagnosed and treated according to a standard, predefined protocol guided by VOG results using automated, evidence-based decision rules. We will compare the impact of this VOG-guided care pathway relative to standard care on ED diagnoses, diagnostic resource utilization, costs of diagnosis, treatments applied, and short-term outcomes. We hypothesize that VOG-guided diagnosis and management of acute vertigo or dizziness in the ED will (1) improve diagnostic accuracy and increase correct treatment for vestibular disorders, (2) reduce diagnostic costs, and (3) offer the potential to improve patient health outcomes. Results from this study could transform care for millions of ED patients with vertigo, offering a higher-quality, lower-cost alternative to current practice.